[elbatawy]

Hello all,

I am trying to compute the Favre average in my source code `.C`files in OpenFOAM 1612+. I am working on comressible flow and i have defined the main Terms of Favre Reynolds transport equation .
What i can not compute, is the Favre average, which is defined as follow
``````math \tilde{u} = \frac{\overline{ρu}}{\overline {ρ}} ``````

As example i can provide one of the Terms of the equation, R Term :
``````R_{ij} = \rho u_i u_j - \rho \tilde{u}_i \tilde{u}_j``````

I have tried to `average()` and `timeAverage()` and another ways to define the time average of the Favre average but nothing is working with me by compiling.



There were thinking that i can define it by using `interpolate()` for terms that needed time average in Favre average as `\rho U ` and `\rho`and in the post processing would be replaced with the time average and compute it.

Because i can not simply define the Favre average and proceed the time average in the post processing, becaue


``````math \tilde{u} = \frac{\overline{ρu}}{\overline {ρ}} ``````
not equivalent to
``````math \tilde{u} = \overline{\frac{ρu}{ρ}} ``````

Any suggestion or Help would be appreciated !